NAME

ud − uucp/mail network daemon

SYNOPSIS

ud [ −n name_of_unix ]

DESCRIPTION

ud connects through the EXOS on-board rlogin server to a special xty device and waits for some program (presumably uucico) to open the xty device and send a string identifying a system to connect to.  ud then uses the rlogin protocol to establish a connection to the system name identified by the string.  The effect of ud is to allow uucico network as if it were directly connected to that system over a modem or RS-232 wire. 

ud attempts to determine when and if the process on the special xty device has exited.  Upon so determining, ud kills whatever children it has and goes back to listening for a new string. 

ud, after making the socket(3) and connect(3) calls, sends four null characters and reads one null character.  This reading and writing is required of the rlogin client when talking to the EXOS on-board rlogin daemon. 

The default name_of_unix is /vmunix. 

EXAMPLE

To use ud as a network mailer, add a line to the /usr/lib/uucp/L.sys file for each system to be called.  The system name should be the same as used in /etc/hosts.  If you want to use aliases, add additional lines to L.sys.  Designate ttyT8 as the device.  The login sequence differs from a normal uucp login sequence in that it begins by expecting nothing and by sending the remote system’s name.  Subsequent to this, a normal uucp login sequence ensues.  For example, L.sysentries for a system named "excelan" (alias "xln") might look like this:

excelan Any ttyT8 9600 ttyT8 "" excelan assword "^M^M" in:-EOT-in: uucp assword: sesame
xln Any ttyT8 9600 ttyT8 "" xln assword "^M^M" in:-EOT-in: uucp assword: sesame

Of course, the uucp L-devices file must also be set to have /dev/ttyT8 as a direct line at 9600 baud.  The /dev/ttyT8 device is determined by the maximum number of xty devices defined in the UNIX kernel.  This number is currently eight.  Do not place a login listener on the this device. 

ud is normally started from /etc/rc. 

FILES

/dev/ttyT8special xty device used by ud connections
/vmunixdefault kernel namelist

SEE ALSO

uucp(1), mail(1)
D. A. Nowitz, Uucp Implementation Description

BUGS

If your uucp installation does not work properly, ud will not work. 

Version 2.4  —  May 08, 1986